1. Field of the Invention
The present invention relates to a vehicle lamp and more particularly to a marker lamp for a vehicle called a tail and stop lamp.
2. Prior Art
A vehicle lamp called a marker lamp for a vehicle such as an automobile tail and stop lamp functions as a tail lamp and as a stop lamp by way of emitting red lights at two different levels of intensity. When it functions as a tail lamp, it emits red light of low intensity; and when it functions as a stop lamp, it emits red light of high intensity.
A conventional tail and stop lamp uses as a light source an incandescent lamp that has two filaments and is called double (W) filament bulb. When it functions as a tail lamp, it lights the filament with an output of 5 W (watt); and when it functions as a stop lamp, it lights the filament with an output of 21 W.
Recently, the benefits of using a light-emitting diode as a light source for a marker lamp for a vehicle have drawn attentions, and a light-emitting diode has been employed as a light source for a tail and stop lamp.
Since light-emitting diodes consume little electric power, it is preferable to use light-emitting diodes as a light source of a lamp mounted on an automobile which, within a limited space, is only capable of loading a power source (i.e. battery) that has only a limited capacity. Further, light-emitting diodes takes a shorter period of time from when a current is supplied to when they reach the maximum intensity compared to incandescent lamps. Thus, light-emitting diodes provide good responsiveness to braking operation and are used preferably for assuring the traffic safety.
When arranging light-emitting diodes for the number that is sufficient enough to secure a required light amount as a stop lamp so that they function as light source of a tail and stop lamp, the lamp, in order to function as a tail lamp, needs to be lit in a lower intensity compared to when the lamp functions as a stop lamp. For this purpose, a circuit for varying luminous intensity into two levels between when the lamp functions as a tail lamp and when it functions as a stop lamp is required. However, such a control circuit is expensive, resulting in a problem that the cost of the tail and stop lamp tends to become high.
Accordingly, it is an object of the present invention to provide a marker lamp for a vehicle that can be manufactured at low cost, while making the maximum use of benefits of light-emitting diodes particularly for a good responsiveness to braking operation of a vehicle.
The above object is accomplished by a unique structure of the present invention for a vehicle marker lamp that has a tail lamp function and a stop lamp function in which the tail lamp function allows the rear of a vehicle to be recognized from behind while driving in the dark, and the stop lamp function allows the braking of a vehicle to be recognized from behind while braking; and in the present invention,
the marker lamp is comprised of a bulb, a plurality of light-emitting diodes, and a reflector which are provided in a lamp chamber defined by a lamp body and a front cover that covers the front of the lamp body, wherein
the bulb is positioned at substantially the center of the reflector,
the reflector is formed with a primary reflective surface and a plurality of openings in which the primary reflective surface reflects the light from the bulb substantially forward, and
the light-emitting diodes are disposed so as to face forward through the openings of the reflector; and
the tail lamp function is executed by lighting the bulb, and the stop lamp function is executed by lighting the light-emitting diodes.
In the marker lamp for a vehicle according to the present invention, the bulb is used as the light source for the tail lamp which is always lit while driving in the dark and is less responsible in terms of functional responsiveness, and the light-emitting diodes having an excellent responsiveness are used as the light sources for the stop lamp for which responsiveness during braking is important. Thus, the lamp well contributes to the traffic safety. Further, since the marker lamp does not require a circuit for lighting the light-emitting diodes in two levels, the lamp can be manufactured at low cost. In addition, the bulb, which consumes a large amount of electric power, is lit with 5 W power output to function as a tail lamp; and the light-emitting diodes are employed in place of a filament that requires an output of 21 W. As a result, the entire electric power consumption can be small.
Furthermore, when the marker lamp functions as a stop lamp, the portions different from those that are lit when it functions as a tail lamp are lit in a high intensity. Thus, the manner in which the lamp is lit differs greatly between when it functions as a tail lamp and when it functions as a stop lamp. This gives a strong impression to a person who sees the lamp, for example, the driver of a vehicle behind and the like, drawing a great amount of attention. Also from this aspect, the marker lamp of the present invention well contributes to the traffic safety.